-george b



Patented JCI1,'7,`I8GO.

r. IT

(No Model.)

G. B. PRESCOTT,J1-. DISTRIBUTION CE ELECTRICITY EY SECONDARY EAIIEEIES.

Ww Q r UNITED vSTATES PATENT OFFICE.

GEORGE B.' PREsOoT'r, JR.,OE NEWARK, NEW JERSEY, ASSIGNOR' To THE EmicrnicgiL, ACCUMULATOR COMPANY. on NEW YORK, N'Y.

oisimsUTloN F ELECTRICITY BY' SECONDARY BATTERIES.

. sPcrF'IarI-ON foi-ming part'- of Letpersratest No. 418,748, dated January 7, 1890.

` Appunti@ and november 8,1889. serio No. 829,687. .ma steun' To qll whom may concern."

"Beit known that I,-GEORGE B. Panscorr, Jr., a citizen of'the'Unit'ed States, and a'resi- .'h'dent ofNewark," inthe county of'.Essex and 5j State' of New Jersey, have invented certain new and useful Improvements in the Distrilint-ion of Electricity by Secondary Batteries,

` 'of which thefollo'iving-ie a specification'.

. My invention is. an improvement inthe :Q .disribution of electricity by secondary bat- "teri-es.- f 'j 1' The invention contemplatesthe use of a i f primary generator oelec'tricity located at a centrahstatiomandone or more sub-stations, i at each of which there is located'a' secondary 1 battery anda working-cireuit to be'supplied "thereby: The main and sub stations are to ;be connected bydwo or'more main 'leadS, calledv the charging-eirouit In this lar- :o' 'rangement of apparatus, when the dynamo is 1- beingcpera'ted to charge t-he battery at any given station and the 'working-circuitis simul- 'taneously supplied from the battery, it happens that the excessive electro-motive fome z3 necessarilyem'ploye'd to charge the batteryl isl "5 nianifestandisinjuriously active in the w0rk' 'n' i' ing-circuit.- Myi'nven tion is designed'to obvif atcthis 'diiiculty by the employment of apparatus automatically operative; and it most 3p particlarly relates to the A.ctmstructionauch (arrangement ofapparatus by which the result is accomplished. 'In acircuit-connecting opposite termirals of the working-citcuitl place an'electrfY-nag- 35. net of high resistance, responsive. to varia- 'tions in electro-motiveforce. Thisl is preferably in the forni` of a solenoid, and controls .'--the localcircuit operating-'the switch. In position to be inserted and withdrawn with .46 respect to the working-circuit I place a s'eries of cells yieldinga counter electro-motive iforce and havin g'small storage capacityf The lswitch or circuit-changer consists of a balanced bar having a series of contacifpoin'ts operatingin a series of fixed mercury-cups. This forms the means for inserting and removing the counterelectro-Inotive-fO'rce cells' with re- .spect to the 'workiiig-circuit. This switchbar isvupon a friction-bearing,so arranged that 5o -the'bar vyillremain'in any position to which.

electrical contacts n and n',

it is mo'ved or in which itis placed until again positively moved by suitable electro-magnetic devices in the local'circiiitl' y The accompanying drawing illustrates my invention. .55

' -D is a dynamo-electric machine located at a central station. It is connected by charging-mains C C with one or more sub-stations. 'At each sub-station thereisa secondary battery-B and a switch S for cuttingit in and 6o out of the charging-mains.

Battery B supplies a Vworking-circuit a' x, containing lamps I. In the workihg-circuit f there is a seriesfof counter electro-motiveforce cells c `c c?, under control of the switch A', operating through tap-wires l, 2,13, anda.

PM is anelectro-magnetic device responsive to variations in electro-motive force, located in' .a circuit 17, connecting opposite leads of the'working-circuit m vat a pointA of 7o average potential.

' A isa switch-bar suitably supported on' a t* friction-beardng atffr, so vthat it wi11 retain whatever angular position it is placed in.

There is adash-pot dfor rendering its movement sluggish, and a weight w for imparting a-'delicate balance to the bar. There is a solenoid magnet M,-having its core attached to bar A'on one sid'e of its support', and there is asimilar magnet M', having its core simi- 8o larlyattached to barA on the opposite side of its support.` q qq are fixed mercury-cup formingl terminals for the tap-wires l 2 3 4, and into which the electrical contact-points on the end of bar A dip.

The core-armature o of magnlet carries a contact-point p, and is attached to. an adjustable retractile spring i. Contact-point p has limitingstops consisting of the fixed 9o Local' 'battery E is in a wire 20, connectedwith contactpoint p.A Wire 21 `connects contact-point 'n with return-Wire 2O and'includes the coils of magnet M in its circuit. Wire 19 connects 95 'contact-point n with return-wire 20 and includes the coils of magnet M in its circuit.

As shown in the drawings, battery B is re ceiving charge from thc mains C C, and the `Workingt-circuit is being also'supplied roo VILBLE COPY felation of this apparatus that the variations with' electrical energy. The electro-motive ving local circuit via'E, 20, M, 39, n', and p,

thus ca u'sing M to draw down bar A until the oonlaobpoint attbeextreme right end ot bar 'A leaves .mercury-cup q, thus breaking the short circuit around counter electro-motiveforce cell'c. This immediately lowers the dierence of potential at the terminals of nirc'uit 17 to approximately the normal amount, andthe contact between and n is immediately broken, p again ta ing its normal or midway position, and the switch-arm A, owin g toits frictionalbearin'g, maintaining the position to which the 'operation carried it. Should the electro-motive force again rise, precisely the same operation is repeated, result ing Vin the introduction of a second counter4 electro-motive-force cell c andthe tetu rn of contact p toa normal position when normal conditions are'restored.' Should the charging-current b'e removed or the difference cf potential at the'terininals of current 17 drop or any reason; contact-.point 4pis retracted by the spring 1' acting againstthe force exerted by magnetic device'PM, and circuit is closed E, 20, M', 21, n, and p, and magnet M' attracts its end 'of .switch-bar A. Wh'en the equilibri'm is egainrestored by thus cutting cnt .one or more counter electro-1notlveforce cells, the parte resume the position substantially as shown, and4 the eiec'tro-motive torce in the working-circuit is thus automati- 'cally 'maintained substantially uniform.

It has been assumed in describing the opof potential at* .e lamp terminals are due to the operations of the charginggenerator; but the same variations may be produced by variations of load in the working-circuits, and

whenever variations due to this or other causes are apparent my arrangement of apparatus is equally efficient in automatically restoring normal conditions.

.Vhatl claim, and desire to secure by Letrs late'nt, is-

.L The combination of a primary generator of electricity. a secondary battery, a working-circuittherefor, a series of counter elecy tro-motii'eiorce cells, .an electromagnetic switch or circnitfchanger for introducing and withdrawing said oeils with respect te the workingcircuit, consisting of a bar pivoted upon .c frictionbearing, a magnet for moving said bar in one direction, a magnet for moving' said bar in the opposite direciioma magnet in a circuit connected to opposite terminale of the working-circuit responsive to va riations in electr-emotive forcctand a localcircnit cperating the two istfnamed magnets under control of tue second-named magnet, substantially as described.

2. The innination of a source of electricity, a working-circuit therefor, a 4serie!! 0f.- counter electro-motive-fome cells, an electro magnetic switch or circuit-changerztorvaryin the position of auch cells with respect to sai upon a rict-ion-bcaring, a magnet for moving said bar in one direction, amaguet for moying 4sai {bar in the opposite direction, a magnet in a circuit connected tooppoeite terminels of the working-circuit, responsive to variations in electrcmotive foros, and a local nir-cuit operating the two tiret-named magnets and controlled by the secondlnamed magnet, substantially as described.

. 3. The combination of a'sonre of'electrlcityJ a working circuit therefor, a series of counter eiectro-motivelforce cells, an electromagnetic switcher circuitfehanger for varying the'p'osition of such cells with respect to said working-circuit, consisting of a bar pivoted upon a frictionbearing, a dash-pot device, a magnet for moving said bar in one direction, a magnet for moving said bar in 4the opposite direction, a magnet in a circuit connected to 'opposite terminals of the workingcircuit, responsive to variations iu electromotiveforce, and a local circuit operating the `working-circuit, consisting of a bar pivoted" i two first-named magnets and controlled by the second-named magnet, substantially as described.

Signed at the city of New York, inthe county of New York and State of New York, this 6th day of November, A. D. 1889.

eso. B. PREsCoTT, JR.

Witnesses:

V. G. SCHAUMBURG, Darm-tr. E. DELAVAN. 

